Hi, 

This post is an explanation on mails which are not sent or received by end users. A good thing to know before continue reading is that Betty Blocks does not provide any mail services, but gives you full possibilities to configure this by yourself. 

Most of the time, this is caused by one of the following situations:

1. You are still using demo settings for your app. In this case, you're only allowed to send emails from appname@betty.app. Please check or change settings as appropriate for your application/organization in the Mail form tab. How you work with this form is described here.
2. You are using Mandrill as a mail service. Sometimes it takes more time than expected to send the mails. Also, it's a possibility that the mail address of the receiver is blocked in Mandrill. Do make sure, you comply to the current GDPR regulations for the EU. For more information, click here. 
3. You are using a custom SMTP server. There can be a delay in sending the emails at the SMTP server. 
4. You are experiencing a hard bounce. This means the mail address you're trying to reach, no longer exists.
5. You are experiencing a soft bounce. This means the receiving SMTP mail server is currently offline and is not possible to process the current request. It will be retried later on, meaning the email will be sent at a later moment in time.
6. Check if the Send Mail event is triggered, by enabling logging and debug logging, and do an extra test run for your action.